Convert OBJ to STL Online — Free
Upload a Wavefront OBJ file and download it as Stereolithography. Runs entirely in your browser — no server uploads.
About These Formats
Wavefront OBJ
OBJ is a simple, human-readable text format that stores 3D geometry (vertices, faces, texture coordinates, and normals). It is one of the most universally supported formats.
Used with
Blender, Maya, Cinema 4D, 3ds Max, ZBrush, and virtually any 3D application.
Stereolithography
STL stores only triangulated geometry — no colors, textures, or animations. It is the de-facto standard for 3D printing slicers and CAD software.
Used with
3D printing slicers (Cura, PrusaSlicer, Bambu Studio), CAD tools, rapid prototyping workflows.
What Transfers from OBJ to STL
A breakdown of which data survives the OBJ-to-STL conversion.
3D Geometry
Vertices, faces, and normals always transfer
Textures & Materials
STL is geometry-only — textures are discarded
Animations
OBJ does not store animations
Vertex Colors
OBJ does not support vertex colors
Multiple Objects
Multiple meshes merged into one on export
When to Convert OBJ to STL
Convert OBJ to STL when you need to 3D print the model. STL is the universal format for slicing software like Cura, PrusaSlicer, and Bambu Studio. Note that STL contains geometry only — colors and textures from the OBJ source will not be included.
OBJ to STL — What to Know Before Converting
STL stores raw triangulated geometry with no colour, material, or texture data. This is intentional for 3D printing — slicers (Cura, PrusaSlicer, Bambu Studio) apply their own material and print settings. Before slicing, verify the mesh is watertight: open meshes with holes or non-manifold edges are a common cause of slicing errors.
OBJ references textures via a companion MTL file — the converter needs both to preserve materials. If only the OBJ is uploaded without its MTL and texture images, the output will be an untextured mesh.
Other OBJ Conversions
Tips for the Best OBJ to STL Result
Run the STL through a repair tool (Meshmixer, Netfabb, or PrusaSlicer's built-in repair) to fix non-manifold edges and holes before printing.
This converter outputs binary STL, which is ~6× smaller than ASCII STL and preferred by all major slicers.
STL stores no unit information. In your slicer, confirm the scale explicitly — FDM printers work in millimetres, but some CAD tools export in metres.
Minimum wall thickness for reliable FDM printing is ~1.2 mm. Review thin sections in the slicer's layer preview before printing.
Common Reasons to Convert OBJ to STL
- →FDM and resin 3D printing: the universal input format for Cura, PrusaSlicer, Bambu Studio, ChituBox, and all major slicers
- →3D print services: Shapeways, Materialise, Craftcloud, and local print bureaux all accept STL as their standard format
- →CNC milling: many CAM packages accept STL geometry for toolpath generation
- →Physical validation: printing a scale model to check form, proportion, and fit before committing to production tooling
Frequently Asked Questions
How do I convert OBJ to STL?
Upload your .obj file using the tool above, confirm the source format is set to OBJ and the target is STL, then click Convert. The file processes in your browser and you can download it immediately.
Does converting OBJ to STL preserve textures?
STL stores geometry only. Textures and materials will not be included in the output.
Is this converter free?
Yes, completely free. No account, no usage limits, no hidden fees.
Are my files uploaded to a server?
No. All processing happens locally in your browser using WebGL. Your files never leave your device.